Pope Benedict cancelled a scheduled speech at Rome's most prestigious university after protests by students and professors over the Church's views on science threatened to overshadow the event, scheduled for Thursday.
The protests had begun with a petition by 67 professors who portrayed the Pope as a backward theologian who put religion before science and should not be allowed to speak.
After resisting calls from protesters to scrap the visit to La Sapienza university, the Vatican said today the Pope had decided to postpone the trip.
He had been due to speak at the inauguration of La Sapienza's 2008 academic year and the Vatican said the Pontiff would still provide a text copy of his speech.
"I am very disappointed. You don't have to share the Pope's ideas but you should let him speak," the Italian government minister in charge of universities, Fabio Mussi, told reporters.
The protesters cited a speech he gave nearly two decades ago, saying it showed he would have favoured the Church's 17th century heresy trial against Galileo for teaching the Earth revolved around the sun. The Pope's supporters denied that.
The controversy ballooned into a fierce debate that divided Italians, with protesters questioning the Church's role in secular society and the Church and free-speech advocates accusing the protesters of censorship.